/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements.  See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License.  You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package javax.servlet;


/**
 * ServletContext 属性事件.
 *
 * ServletContextAttributeEvent是为ServletContextAttributeListener提供的事件对象，主要继承了ServletContextEvent，
 * 即ServletContextListener的事件对象，其中保存了ServletContext对象以及修改的属性名和属性值
 *
 *
 *
 *
 *
 * This is the event class for notifications about changes to the attributes of the
 *  servlet context of a web application.
 * @see ServletContextAttributeListener
 * @since	v 2.3
 */
public class ServletContextAttributeEvent extends ServletContextEvent {
	/**
	 * 属性名.
	 */
	private String name;

	/**
	 * 属性值.
	 */
	private Object value;

	/** Construct a ServletContextAttributeEvent from the given context for the
	 * given attribute name and attribute value.
	 *
	 * Constructor.
	 * @param source 受影响的ServletContext.
	 * @param name 属性名.
	 * @param value 属性值.
	 */
	public ServletContextAttributeEvent(ServletContext source, String name, Object value) {
	    super(source);
	    this.name = name;
	    this.value = value;
	}
	
	/**
	 * 获取属性名.
	 *
	 * Return the name of the attribute that changed on the ServletContext.
	 *
	 */
	public String getName() {
		return this.name;
	}
	
	/**
	 * 获取属性值.
	 *
	 * Returns the value of the attribute that has been added, removed, or replaced.
	 * If the attribute was added, this is the value of the attribute. If the attribute was
	 * removed, this is the value of the removed attribute. If the attribute was replaced, this
	 * is the old value of the attribute.
	 *
	 */
	
	public Object getValue() {
	    return this.value;   
	}
}

